1. Field of Invention
This invention relates generally to toy figures or characters having artificial eyes, and in particular to figures or characters of this type in which the eyes simulate, by means of an optical illusion, eyeball movement with respect to an observer whose angular position changes relative to the eyes, whereby the eyes appear to follow the observer.
2. Status of Prior Art
Since the invention deals with artificial eyes that appear to follow the observer as his orientation changes relative to the eyes and therefor simulate animation, the nature of a natural eye must first be considered.
The eye, which is the organ of vision, is a spheroid structure that rests in a bony cavity or socket on the frontal surface of the skull. It is filled with a jellylike, vitreous humor contained within three covering layers: the sclera, the choroid and the retina. The sclera is the outermost layer of eye tissue, a portion of which is visible as the white of the eye. In the center of the visible sclera and projecting slightly therefrom is a transparent cornea that acts as the window of the eye. Underneath the sclera is a second tissue layer, the choroid composed of blood vessels.
As the sclera nears the center of the visible portion of the eye, it merges with a ciliary body containing muscles used in focusing, which body in turn merges with the iris, the pigmented portion of the eye whose center is perforated and appears as the pupil. Back of the iris is a transparent lens. The third and innermost layer of tissue, the retina, contains nerve fibers.
The eyeball is a more or less globular capsule formed by the sclera and cornea together with their contained structure. In a synthetic eye of the conventional type used in play dolls, toy figures and characters, the eye is usually constituted by a transparent plastic dome, within which is a clolored eyeball, the annular region in the dome surrounding the eyeball being in a contrasting color.
The natural eye is sometimes referred to poetically as the window to the soul, for the eye more than any other organ of the body is highly expressive. It is for this reason that most people are disturbed by a blind person whose eyes are not concealed by dark glasses, for these eyes appear to be dead. This has the unfortunate effect of making it seem that the blind person is zombie-like and not truly alive.
The typical artificial eye in a doll or toy figure is also devoid of life, the eye being dull and spiritless. To avoid this negative effect, attempts have been made in toy figures to impart animation to the eyes. Thus, in the Spector U.S. Pat. No. 4,521,205, the eyes in a toy figure take the form of eye openings covered by a transparent lens behind which is the end of a fiberoptic light pipe. Intermittent light is conducted through this pipe so that the eyes are intermittently illuminated and thereby animated.
The approach taken in the Spector patent requires a modulated light source and other components which are relatively expensive. Moreover, an eye which is intermittently illuminated does not give the impression of a natural eye in which the eyeball is capable of movement, for there is no eyeball in the Spector eye, to say nothing of eyeball movement.